Grinding mill with divided feed



' Aug. 27, 1935. E. a. BAILEY El AL 2,012,783

GRINDING MILL WITH DIVIDED FEED Ori-ginal Filed April 4, 1930 2 Sheets-Sheet 1 Q V b.

gwom w Allg- 1935- E. G. BAILEY El Al. 2,012,583 I GRINDING MILL WITH DIVIDED FE ED Original Filed April 4, 1930 2 Sheets-Sheet 2 M 1, .uysmom FIG. 3. W

, Juu! A9 4 ATTBRNE l5 Patented Aug. 27, 1935 UNITED STATES PATENT OFFICE 2.01am GRINDING MILL wrrn mvmnn FEED Ervin G. Bailey, Easton, Pa., and Perry R. Cassidy, Short Hills, and Ralph M. Hardgrove, Westfleld, N. J., assignors to Fuller Lehigh Company, Fullerton, Pa., a corporation of Delaware Application April 4, 1930, Serial No. 441,469

Renewed February 24, 1934 16 Claims.

This invention relates to a grinding mill in which a plurality of rows of grinding balls are used and the material that is to be ground is divided and fed to diiferent rows of grinding balls.

. Air is caused to pick up the fine particles of the an illustrative embodiment of the invention'taken .of grinding balls ll.

along the line l--l of Fig. 2; Fig. 2 is a section along the line 2-2 of Fig. 1; Fig. 3 is a section along the line 3-3 of Fig. l and Fig. 4 is a sec-' tion along the line 4--4 of Fig. 1. V

In the drawings reference character I indicates a base 01' support for the mill to which the base or bottom 2 of the mill is attached by means of bolts 3. The wall 4 of the mill extends upwardly from the base 2 and is supported thereon. The wall 4 constitutes a casing which surrounds the grinding elements and other parts of the machine. A cylindrical outlet 5 for the fine particles of ground material is provided at the top of I the casing 4.

A wind box 6 is provided around the wall 4. It is provided on one side with an access door 6 and on the other side with an inlet 1 forair under pressure from any convenient source.

A lower stationary grinding ring 8 rests upon a support 9 at the lower portion of the mill and is provided with a ball race ID for a'circular row A rotatable driving ring I2 is located above the row of balls I l and is provided with ball races l3 along its upper and lower edges. A circular row of grinding balls I 4 is located above the ring I2 and contacts therewith.

A yoke l5 having arms that extend into spaces between lugs l6 along the inner surface of the rotatable ring I2 is driven by the vertical shaft II, which is in turn driven through reduction gearing by the motor l8. The vertical spaces between the lugs l6 permit the ring l2 to move up and down short distances with respect to the yoke l5.

A non-revoluble ring l9 with a ball race 20 along its lower edge is located above the row of balls 14. on the upper edge of the ring l9 and rods 22 are provided for pressing downwardly upon the lugs 2|. Springs 23 are provided for pressing the rods 22 downwardly and the screws 24 are provided for adjusting the tension of the springs. Housings 25 are provided for the springs 23 and Lugs 2| are provided at intervals.

rods 22, these housings being located in recesses in the casing 4. Screw bolts 21 are provided for. keeping the housings 25 in place.

A feed inlet 28 is provided from the upper por- /tion of the mill for feeding the material that is to be ground into the spaces between the rows of grinding balls, from which spac'esthe grinding material passes outwardly through the rows of balls.

A cone 29 extends upwardly from the ring I2 and a dividing box for the material that is being. fed is provided at the apex of this. cone so that the material to be ground is divided, a part going to the row of balls l4 and another part tothe row of balls H. The dividing box comprises two quadrant-shaped sections 30 with openings 3| at the bottom thereof so that the material which enters these quadrant-shaped sections passes below the cone 29 and remainder of the material passes along the upper surface of the cone 29 tionary, truncated cone 33 is carried by the ring 8, the edges of the cones 32 and 33 overlapping. These two cones guide the material that passes through the openings 3| and feed it through the row of balls H to be ground.

A cylindrical skirt 34 extends from the upper portion of the box 6 to a plane below the upper edges of the balls l4. Plows 35 are attached to the outside of the driving ring l2 for lifting the ground material into the path of the air that sweeps under the edge of the skirt 34. Air jets may be provided in the lower portion of the space outside of the balls II to lift. the ground The operation is as follows: v

The material to be ground is introduced through the inlet 28 and half of it passes along the' upper side of the done 29 and is passed through the row-of balls l4 to be ground, while the remainder passes through the openings 3 along the cones 32 and 33 to the row of balls II to be ground." The material which passes through the row of balls I4 is ground and passes downwardly, while the remaining material is ground by the balls II and passes outwardly and is mixed with the ground material from the balls H. The plows 35 throw the ground material upwardly into the stream of incoming air which carries ofl' the fine particles, the coarse '65 particles falling back and becoming further ground by the balls ll.

Air under pressure which enters through the inlet 1 passes under the lower edge of the skirt 34, picking up the finely ground material and carrying it upwardly over the upper edge of the cone 36 where larger particles drop downwardly through the opening 31 to the balls H and I4 while the air and fine particles pass out through the outlet 5.

While in accordance with the provisions of the statutes we have illustrated and described herein the best forms of our invention known to us, those skilled in the art will understand that drawings may be made in the form of the apparatus and character of the carrier medium disclosed without departing from the spirit of the invention covered by our claims, and that certain features of our invention may sometimes be used without a corresponding use of other features. In our claims, the word air" is used generically to cover any gaseous carrier medium suitable for removing pulverized material in the manner described.

We claim:

1. In a grinding mill, a casing enclosing a plurality of circular rows of grinding balls, a driving ring located between said rows of balls, means for feeding material to said balls to be ground, means for dividing the material to be fed 'to said circular rows of balls independently along the inside of said rows of balls, and means to cause air to pass through said casing and pick up fine particles ground by said balls.

2. In a grinding mill, a plurality of circular rows of grinding balls, a driving ring located between said rows of balls, means for feeding material to said balls to be ground, means for dividing the material to be fed to said circular rows of balls independently along the inside of said rows of balls, means to cause air to pick up fine particles ground by said balls and plows located outside of one of said rows of balls.

3. A pulverizing mill comprising a casing, upper and lower circular rows of rolling grinding elements in said casing, means for feeding material to be pulverized independently to said rows of grinding elements in parallel and in the same direction therethrough, and means for causing an air current to pass through said casing and remove the material pulverized by said rows of grinding elements.

4. A pulverizing mill comprising a casing, upper and lower circular rows of rolling grinding elements in said casing, means for feeding material to be pulverized to said rows of grinding elements independently and simultaneously, and means for causing a current of air to carry away the material pulverized by said rows of grinding elements upwardly through said casing.

5. A pulverizing mill comprising a casing, upper and lower circular rows of rolling grinding elements in said casing, means for feeding material to be pulverized to said mill, means in said mill for dividing the material supplied between said rows of grinding elements, and means for causing a current of air to pass through said casing and carry away the material pulverized by said rows of grinding elements.

6. A pulverizing mill comprising upper and lower circular rows of rolling grinding elements, a driving ring located between said rows of grinding elements, means for separately feeding material to be pulverized to said rows of grinding elements, means for causing a stream of 'air to pick up material pulverized by said upper row of grinding elements, and means for conveying material pulverized by said lower row of grinding elements into the path of flow of said air stream.

'7. A pulverizing mill comprising a casing, upper and lower circular rows of rolling grinding elements in said casing, means for separately supplying material to be pulverized to the inner sides of said rows of grinding elements, means for passing an annular air stream past the outer side of said upper row of grinding elements to convey materialpulverized thereby to the upper part of said casing, and means for conveying pulverized material from the outer side of said lower row of grinding elements into the path of flow of the air stream.

8. A pulverizing mill comprising a casing, a lower grinding ring in said casing, a lower circular row of rolling grinding elements in contact with the upper surface of said grinding ring, an upper non-rotary grinding ring in said casing, an upper circular row of grinding elements in contact with the lower surface of said upper ring, an intermediate rotary grinding ring having its upper and lower surfaces contacting respectively with said upper and lower rows of grinding elements, means for supplying material to be pulverized to said rows of grinding elements, means for passing an annular air stream past said upper row of grinding elements to convey material pulverized thereby to the upper part of said casing, and means for conveying pulverized material from said lower row of grinding elements into the path of flow of the air stream.

9. A pulverizing mill comprising a casing, a lower grinding ring in said casing, a lower circular row of rolling grinding elements in contact with the upper surface of said grinding ring, an upper non-rotary grinding ring in said casing, an upper circular row of rolling grinding elements in contact with the lower surface of said upper ring, an intermediate rotary grinding ring having its upper and lower surfaces contacting respectively with said upper and lower rows of grinding elements, means for separately supplying material to be pulverized to the inner side of said rows of grinding elements, means for passing an annular air stream past the outer side of said upper row of grinding elements to convey material pulverized thereby to the upper part of said casing, and means for conveying pulverized material from said lower row of grinding elements into the path of flow of the air stream.

10. A pulverizing mill comprising a casing having an outlet for pulverized material in the upper part thereof, a lower grinding ring in said casing, a lower circular row of rolling grinding elements in grinding contact with the upper surface of said lower grinding ring, an upper non-rotary grinding ring in saidcasing, an upper circular row of rolling grinding elements in contact with the lower surface of said upper grinding ring, an intermediate rotary grinding ring having upper and lower surfaces contacting respectively with said upper and lower rows of grinding elements, means for separately supplying material to be pulverized to the inner sides of said rows of grinding elements, vmeans for passing an annular air stream past the outer side of said upper row of grinding elements to convey material pulverized thereby to said casing outlet, means for conveying pulverized material from the outer side of said lower row of grinding elements to said casing outlet, and means for returning coarse material separating from the pulverized material passing to said casing outlet to said upper and lower rows of grinding elements.

11. A pulverizing mill comprising a casing, a lower track within said casing provided with a plurality of balls maintained therein by an intermediate track, a plurality of balls on said intermediate track' maintained therein by an upper track, means for feeding material to the two pairs of tracks and associated balls, means for causing an annular stream of air to enter said casing above said lower track and associated balls and adjacent the discharge side of the balls on said intermediate track to entrain material delivered from said intermediate track by centrifugal force and carry the entrained material upwardly through said casing, and mechanical means for effecting relative movement between each pair of tracks.

12. A pulverizing mill comprising a casing, a

I lower grinding ring in said casing, a circular row of rolling grinding elements in contact with an uppersurface of said ring, an upper grinding ring in said casing with a lower surface in contact with said grinding elements, means for relatively rotating said upper and lower grinding rings, means for feeding material to be ground to the inner side of said row of grinding elements, a discharge port in the top of said casing, and means for causing an annular stream of air to entrain pulverized material at the outer side of said row of grinding elements and pass upwardly' and inwardly to the discharge portthrough a substantially unobstructed space immediatelyabove and within said upper grinding ring, in which space the heavier particles of the material-entrained separate and return by gravity to the inner side of said row of grinding elements for further pulverization.

13. In an air-swept grinding mill, a substantially air-tight casing having an outlet for pulverized material in the upper part thereof and enclosing a plurality of vertically spaced grinding rings and a circular row of rolling grinding elements positioned therebetween and cooperating therewith to form a grinding stage,- means for feeding material to be pulverized to the inner side of said row of grinding elements, and means including, an annular flow-directing baiiie having its lower end terminating adjacent the outer side of said row of grinding elements for directing an annular stream of air adjacent to and" mainly past the outer side of said row of grinding elements 'to pick up material leaving said grinding stage and convey said material upwardly to said casing outlet.

14. In an air-swept grinding mill, a substantially air-tight casing having an outlet for pulverized material in the upper part thereof and enclosing an elastically loaded non-rotary upper grinding ring, a rotary lower grinding ring, and

a circular row of rolling grinding elements positioned there-between and cooperating therewith to form a grinding stage, means for feeding material to be pulverized to the inner side of said row ments and said casing.

of grinding elements, anannular flow-directing ments in contact with the upper surface of said lower grinding ring, an upper non-rotary grinding ring in said casing, an upper circular row of rolling grinding elements in contact with the lower surface of said upper grinding ring, an intermediate rotary grinding ring having its upper and lower surfaces contacting respectively with said upper and lower rows of grinding elements, all of said .grinding rings being spaced from said casing, means for supplying material to be pulverized to said upper row of grinding elements, means for passing an annular air stream upwardly through said casing to convey material pulverized therein to the upper part of said casing, said air stream being directed to enter the space between said grinding rings and casing at a level above the level of said lower row of grinding elements and pass upwardly adjacent the discharge side of said upper row of grinding elements, and a series of arcuately spaced plows mounted on said intermediate grinding ring at the outer side thereof, said plows being arranged to extend downwardly into and terminate above the bottom of the space between said lower row of grinding elements and said casing.'

16. An air-swept pulverizer comprising a-casing, a'lower grinding ring in said casing, a lower circular row of rolling grinding elements in contact with the upper surface of said lower grinding ring, an upper grinding ring in said casing,

to enter the space between said grinding rings and casing at a level above the level of said lower row of grinding elements and pass upwardly adjacent the discharge side of said upper row of grinding elements, and a plow mounted on said intermediate grinding ring at the outer side thereof and arranged to extend downwardly into the space between said lower row of grinding ele- ERVIN G. BAILEY. PERRY R; CASSIDY. RALPH M. HARDGROVE. 

